Interference suppression schemes for space-time Trellis coded CDMA systems

The paper considers various interference suppression schemes for space-time trellis coded (STTC) WCDMA systems and analyzes their performance. A Rake matched filter over frequency selective multiuser multiple-input multiple-output (MIMO) channels is first investigated. Then a linear minimum mean-squared error (LMMSE) detector is presented, which suppress interference in STTC WCDMA systems generated from multipath, multiuser and multiple antennas propagation. The bit error rate performance of the space-time LMMSE receiver is analyzed. To obtain further performance improvement, a more efficient iterative MMSE scheme is considered. The iterative receiver performs soft interference cancellation for every user´s every antenna based on a combination of the MMSE criterion and the turbo processing principle. It is shown that these space-time detectors have a potential to provide significant capacity enhancements over the conventional Rake matched filter receiver.